Inside Machines: Upgrading Boeing 777 Wing Fastening Machine

Rosie the Riveter of WWII fame has long-since been replaced by automated descendents. Boeing Company has been doing automated assembly of aircraft components for decades. In fact, earlier generations of wing fastening machines are ready for rejuvenation using newer technology controller systems and touchscreen human machine interfaces (HMIs). To assist with the upgrades, Boeing engaged Concept Systems Inc., a system integrator with experience in the latest automation and machine vision technologies.

A recent project involved retrofitting the wing fastening machines that Boeing uses to make wings for the 777 commercial aircraft. These machines, originally manufactured by Gemcor of West Seneca, N.Y., were installed at Boeing’s Everett, Wash., plant. Nine of these machines are in use on the 777 line. At any given time, there are four wing panels being assembled, with two Gemcor machines working on each panel section, installing over 70,000 fasteners per wing set, one at a time.

Gemcor machines use fasteners to attach the wing skin panels to the underlying wing stringers in a four-step cycle. The machine drills and countersinks the holes, places each fastener in its hole, installs the fasteners with a specified force, and then shaves the top of the fastener flush with the wing panel. The machine is also capable of inserting bolts with a similar operation, first drilling and countersinking the holes, applying sealant, and then inserting bolts in the holes.

The control system upgrade project began in 2005 when Boeing’s 777 Production and Equipment Services Gemcor Team, as part of the company’s commitment to continuous improvement of manufacturing operations, decided to upgrade the machine’s electrical systems and controllers. The machines on the 777 line were originally installed in 1992 and had been added to and modified several times since then. With each modification, new wiring was laid on top of old wiring, and the machines were starting to exhibit downtime due to problems with the wiring network that had become difficult to troubleshoot. The original controllers and drives had also become obsolete, and the Boeing Gemcor Team could see opportunities to improve productivity if the machine’s old vision system were replaced with the newest technology, and the operator interfaces were replaced with more user-friendly systems. There were also opportunities to add new automated functions to the machines to minimize operator interface.

To implement all of the machine upgrades, engineers from Concept Systems, an Albany Ore.-based systems integrator with a regional office in Seattle, Wash., worked very closely with the Boeing Gemcor Team. One of the first steps was the review of available documentation for the machines, which consisted of one set of drawings per machine. As the machine controller upgrade brought commonality to all machines, the Concept Systems engineers consolidated the drawings to one set.

The upgrade plans called for removing all of the old wiring and replacing the CNC controller, PLC, motor drives, and motion controller on each Gemcor machine and adding new touchscreen HMIs. In the process, Concept Systems improved the HMIs to standardize the operator interfaces with other wing manufacturing systems in the plant.

One new function that Concept Systems supported was addition of the tack re-sync camera and monitor (tack re-synch refers to the operation of removing a tack fastener and replacing it with an actual fastener). In addition to the main operator consoles that are used to run the machine, Concept Systems added a maintenance console connected to a PC that is used for maintenance programming. The lower operator console consists of a main PanelView operator screen and monitors for the tack re-sync operation, the CNC, and an injector camera that shows the fasteners as they’re inserted.

“When wiring problems would occur with a machine before the upgrade, sometimes the machine would be down for a day or two,” said Fred Rassoulian, Boeing’s Wing Fastening Systems lead engineer. “Now the downtime is minimal. A guess would say that we saved at least a couple of days per month of machine downtime. And with the new HMIs and online maintenance procedures, keeping the machines running and troubleshooting what problems do occur is now a lot easier.”

The quicker fastener placement has also improved the speed of the machine, increasing its capacity. And as part of the upgrade, the machines were made more energy efficient by replacing the air compressor and pneumatic air dryer with more efficient units, helping Boeing win energy credits from the local public utility district (PUD).

“Concept Systems understood Boeing’s requirement for absolute precision and exacting tolerances,” said Rassoulian. “Concept Systems’ engineer Mike Dodds went over every step in the test and acceptance process in detail and made sure that the new system functioned successfully to meet Boeing standards.”

- Michael Gurney is co-CEO and vice president of sales and marketing, Concept Systems Inc.